Braking Unit Research Articles

Effects of 6-Week Weighted-Jump-Squat Training With and Without Eccentric Load Reduction on Explosive Performance.

To compare the effects of 6-week barbell weighted-jump-squat (WJS) training with and without eccentric load reduction on explosive performance. Twenty well-trained male athletes were randomly assigned to either an experimental group (n = 10) or a control group (n = 10). Participants completed 12 WJS training sessions (6 sets of 5 repetitions of barbell back squat at 30% of 1-repetition maximum[1RM]) twice a week over a 6-week period. While thecontrol group used 0% eccentric loading (ie,traditional WJS), theexperimental group utilized a 50% eccentric loading reduction with a mechanical braking unit (ie,eccentric load set at 15% of 1RM). Performance assessments, including countermovement jump, 20-m sprint, standing long jump, and 1RM barbell back squat, were conducted both before (pretests) and after (posttests) the intervention. Both theexperimental group and thecontrol group demonstrated a significant increase in countermovement-jump height (+6.4% [4.0%] vs +4.9% [5.7%]; P < .001) and peak power output (+2.3% [2.7%] vs +1.9% [5.1%]; P = .017), faster 20-m sprint times (+9.4% [4.8%] vs +9.2% [5.5%]; P < .001), longer standing long jump (+3.1% [2.5%] vs +3.0% [3.3%]; P < .001), and higher 1RM back squat (+6.4% [4.0%] vs +4.9% [5.7%]; P < .001) from pretests to posttests. However, there was no significant condition × time interaction for any variable (all P ≥ .294). Both WJS training methods, with and without load reduction in the eccentric phase, effectively enhance explosive performance. Nevertheless, athletes in later stages of injury rehabilitation or intense training may find reducing eccentric load a more tolerable strategy for achieving similar performance gains compared with traditional isoinertial loading.

Adaptive MATLAB GUI for Hydraulic Brake Stopping Distance Simulation

The crucial segment of any vehicle is the braking unit which decides the vehicle’s performance and passenger safety on a large quotient. It is highly essential to decelerate the vehicle within a reduced distance to avoid any collision. The stopping distance is also dependent on many characteristics apart from the vehicle itself which are GVW(Gross Vehicle Weight), brake sizing, Road Friction, and other vehicle design parameters. Hereby, the result of any brake system is the Stopping Distance. Therefore, for every vehicle, it is inevitable to design in such a way that meets all requirements to pass the safety standards. In this article, we provide an interactive GUI of Mathematical modelling using MATLAB that depicts the running vehicle simulation while the brakes are applied and highlights the Stopping distance for any given inputs. Here, we have used a novel approach to calculate the stopping distance, given we have all vehicle properties. Importantly, cuts the design phase to a large extent saving an ample amount of time with all ease of access and dexterity. The core features of GUI: One will be able to generate and compare stopping distance and other brake-related results for any two given different design scenarios. GUI is automated so that it can simulate the stopping distance just by providing the brake/vehicle parameters inputs to the interface. Additional functionalities to compare design results for various standards (FMVSS, IS, ECE) can also be done effectively. Keywords: Braking Systems, MATLAB Application, Vehicle Safety, Stopping Distance

A Wear Prediction Framework for Ball-Screw of Electro-Mechanical Brake Unit on Railway Trains

The electro-mechanical brake is a new advancement in railway train braking. Ball-screws are important components of electro-mechanical braking units (EMBUs), and their wear can cause EMBUs to degrade in performance or even fail to function. In this paper, we present a framework for prediction of ball-screw wear with discrete operating conditions as inputs, taking into account the time-varying characteristics of EMBUs. The framework includes determining the contact type, analyzing relative motion, calculating contact deformations, and estimating wear. The contact type is determined based on the quasi-static approach of Hertz theory. A dynamics model using multiple coordinate systems is established to analyze how balls and raceways move in relation to each other. The contact deformations of the ball–raceway contact are determined using numerical calculation. Then, the wear depth increment is calculated using the Archard model. The results of the calculation and the endurance test indicate that the wear on the screw raceway is greater than that on the nut raceway. The effect of velocity is greater than the effect of axial force. The presented calculation framework is reasonable and can be used for predicting EMBU ball-screw wear.

Design and experimental study of electromechanical braking unit based on DOE method

Design and experimental study of electromechanical braking unit based on DOE method

Design and Analysis of Brake-by-Wire Unit Based on Direct Drive Pump–Valve Cooperative

Aiming at the requirements of distributed braking and advanced automatic driving, a brake-by-wire unit based on a direct drive pump–valve cooperative is proposed. To realize the wheel cylinder pressure regulation, the hydraulic pump is directly driven by the electromagnetic linear actuator coordinates with the active valve. It has the advantages of rapid response and no deterioration of wheel side space and unsprung mass. Firstly, by analyzing the working characteristics and braking performance requirements of the braking unit, the key parameters of the system are matched. Then, in order to ensure the accuracy of the simulation model, the co-simulation model of the brake unit is established based on the Simulink-AMESim co-simulation platform. Then, the influence law of key parameters on the control performance is analyzed. Finally, the experimental platform of the brake unit is established. The accuracy of the co-simulation model and the feasibility of the brake-by-wire unit based on direct drive pump–valve cooperative are verified through the pressure control experiment and ABS simulation, which shows that the braking unit has good dynamic response and steady-state tracking effect.

PLC and Computer Based Brake Unit Testing Device for Heavy Vehicles

PLC and Computer Based Brake Unit Testing Device for Heavy Vehicles

A variable stiffness method for pneumatic flexible arms

In this study, a three-degree-of-freedom pneumatic flexible arm with a braking function was designed to overcome the shortcomings of low bearing capacity and insufficient rigidity of existing flexible arms. The braking force was adjusted by controlling the air pressure entering the brake, changing the stiffness of the flexible arm, and enhancing the posture maintainability of the flexible arm. A theoretical model of the braking force and stiffness of a flexible arm was established, and applicable experiments were conducted. The theoretical data were consistent with the experimental results. The braking force linearly increased with the increase of braking pressure, at a brake air pressure of 0.40 MPa. The braking force of a single braking unit reached 276 N. The stiffness nonlinearly increased with an increase in the brake air pressure. At a brake air pressure of 0.4 MPa, the axial stiffness of the flexible arm in the initial state had the highest value of 20 kN/m. The stiffness change in the bending direction of the flexible arm in the spatial bending state was the largest and increased by 12.4 times. The proposed flexible arm exhibited high stiffness and flexible movement; thus, it can be used as a flexible arm to support other end effectors. The proposed variable stiffness method can be practically employed to maintain the posture of flexible robots, which has a high practical value.

Human–Machine Redundant Braking System for Aftermarket Low-Speed Electric Vehicle: Design and Validation

This paper presents the design and experimental validation of a novel human–machine redundant braking system (HMRBS) for aftermarket low-speed electric vehicles (LSEVs) to realise the backup redundancy ability and improve active safety. First, the HMRBS is designed by connecting the electro-hydraulic braking (EHB) unit oil pipelines in parallel with the manual braking (MB) unit through two three-way shuttle valves. Then, the mathematical model of the EHB subsystem is built, and a master cylinder pressure controller with adaptive fuzzy proportion integration differentiation (PID) and a servo motor speed controller with double-closed-loop proportion integration (PI) are proposed to improve the system response performance. Following this, the co-simulation model of the proposed closed-loop system is established based on AMESim and MATLAB/Simulink to validate the feasibility of the proposed control strategy. Finally, the effectiveness of the HMRBS is also validated by test rig and vehicle experiments. The results imply that the modified LSEV with the HMRBS meets the requirements of vehicle active braking ability and manual braking redundancy. Furthermore, the proposed controller can significantly enhance pressure control accuracy compared to the classical PID controller. The deceleration fluctuation and braking distance in the active braking mode are smaller than those in the manual braking mode, indicating that the proposed system makes the braking effect more stable and safer.

Neuromechanical Consequences of Eccentric Load Reduction During the Performance of Weighted Jump Squats.

To quantify the acute effects of a spectrum of eccentric load reductions on neuromechanical adjustments during the performance of weighted jump squats (WJSs). On separate days, 16 well-trained participants performed WJS trials with various eccentric load reductions (0% [body mass only], 25%, 50%, 75%, and 100% [standard WJS] of concentric load) with a mechanical braking unit, while concentric load was set at 30% of peak isometric squat force in all trials. A force platform and a motion-capture system were used to assess neuromuscular performance. Peak power output was 6.2% (4.7%) higher when load was reduced by 50% versus 0% (55.4 [7.8] vs 51.9 [7.6]W/kg; P = .001). Compared with no braking (0.326 [0.059]m), jump height was ∼13% to 17% higher for all eccentric load reduction conditions (all P < .001). Vertical ground reaction forces were progressively lower for 25%, 50%, 75%, and 100% loading conditions (-22.1% [14.6%], -32.3% [10.8%], -42.0% [13.2%], and -46.1% [14.7%]; all P ≤ .001) in reference to body mass only. Eccentric load reduction is advantageous compared with traditional isoinertial loading for improving both jump height and peak power output during the concentric portion of maximal-effort WJS. This practice also decreases mechanical constraints in the lower extremities, which may become beneficial for load-compromised individuals.

Development of Brake Unit with Toe Angle Actuation for Seismic Response Reduction of Caster Wagon

Development of Brake Unit with Toe Angle Actuation for Seismic Response Reduction of Caster Wagon

Mechanical anti-lock braking system using pneumatic system and solenoid valve with low cost manufacturing

PurposeThe Purpose of this study is to prove the possibility of developing low cost mechanical anti – lock braking system (ABS) for the passenger’s safety.Design/methodology/approachThe design methodology of the proposed newer mechanical ABS comprises of two units, namely, the braking unit and wheel lock prevention unit. The braking unit actuates the wheel stopping as and when the driver applies the brake, whereas the wheel lock prevention unit initiates wheel release to prevent locking and subsequent slip/skidding. The brake pedal with master cylinder assembly and double-arm cylinder forms the braking unit, brake pad cylinder, movable brake pad, solenoid valve and dynamo forms the wheel lock prevention unit. The dynamo coupled with the rotor energises/de-energises the solenoid values to direct airflow for applying brake and release it, which makes the system less energy-dependent.FindingsThe braking unit aids in vehicle stops, by locking the disc with the brake pad actuated by a double-arm cylinder. The dynamo energises the solenoid valve to activate the brake pad cylinder piston for applying the brake on the disc. Instantaneously, on applying the brake the dynamo de-energises the solenoid to divert the pneumatic flow for retracting the brake pad thereby minimizing the braking torque. The baking torque reduction revives the wheel rotating and prevents slip/skidding.Originality/valueMechanical ABS preventing wheel lock by torque reduction principle is a novel method that has not been evolved so far. The system was designed with repair/replacement of the parts and subcomponents to support higher affordability on safety grounds.

Temperature Determination in the Two-Disk Braking Unit of a Light Tracked Vehicle’s Transmission on an Inertial Diesel Test Bench

Temperature Determination in the Two-Disk Braking Unit of a Light Tracked Vehicle’s Transmission on an Inertial Diesel Test Bench

Integrated simulation platform for a locomotive braking system

We used a locomotive and a rail car to examine the working principle of a locomotive braking system. We established models of the locomotive braking system, the locomotive dynamics, and the brake disc thermodynamics and, based on the correlation parameters for each subsystem, built an integrated simulation platform for the locomotive braking system based on Simulink and AMESim. Using this platform, we simulated the characteristics of the pneumatic braking unit, the locomotive braking, and temperature increase in the brake disc under emergency braking conditions. We compared our simulation results with experimental data and the results showed that the integrated simulation platform for the locomotive braking system could successfully be used to study locomotive braking control on the vehicle level. We provide a design optimization method for the development of a braking system, the setting of the anti-skid criterion, and early warning of an increase in the brake disc temperature.

Explosive atmosphere ignition source identification during mining plant suspended monorail braking unit operation

Coal dust and methane explosions are some of the most common causes of mining disasters in hard coal mines all over the world, and research continues to be conducted with the purpose of understanding the mechanisms of an explosion, explosion prevention and risk reduction. This article presents the test methodology as well as virtual and bench test results for a braking unit, which constitutes one of the main components of a suspended monorail transport system. The design work and virtual and bench testing were performed as part of a European research programme. The tests were conducted in a dedicated specialist test facility. The tests were based on Polish standard PN-G-46860:2011, concerning braking trolleys employed in mining plant suspended railway systems. The tests also factored in the requirements for non-electrical devices intended for use in explosive atmospheres, including braking systems, as defined in standard PN-EN ISO 80079-36:2016, harmonised with the ATEX directive. The test scope encompassed braking unit operational component temperature measurements using thermal imaging and the contact method, as well as braking distance measurements. Further tests involved virtual simulations of brake pad heating. The tests employed the finite element method (time-varying calculations). Results obtained over the course of numerical calculations indicate that brief brake pad friction face heating, even up to a temperature exceeding 200C, does not result in inward heat propagation towards the brake pad material. This is also confirmed by the measurement results. However, under real conditions, the braking unit would be engaged only during an emergency situation, which would not lead to exceeding the permissible brake shoe material temperature values.

Nature Based Self-Learning Mechanism and Simulation of Automatic Control Smart Hybrid Antilock Braking System

The antilock braking system (ABS) is intended to augment braking effectiveness, maintains understeer and oversteer conditions. The braking system performance is degraded in the case of severe road conditions. The research paper presented the effectiveness of smart hybrid antilock braking system in automobiles. The concept of antilock braking system and manual braking system is anticipated to a single unit to overcome the problem facing in the braking system in vehicles. Lyapunov’s theoretical stability approach is used for the system stability. The concept of smart control development is used to solve system complexity and real time issues in different road conditions. Directional Control Valve (DCV) plays very important role in controlling the flow direction of brake oil. The Electronic Control Unit (ECU) is the slip controller for antilock braking system, which takes inputs from brake pedal, speed of all four wheels and various road conditions, processes the accumulated data to generate corresponding PWM signal for the DCVs. The ignition switch and ECU controls the activation and de-activation of directional control valve. The MATLAB/Simulink, 2015 version and experimental analysis using Automation Studio verified the model behavior in both ABS and manual braking mode. The system performance is analyzed during ignition ‘ON’ and ‘OFF’ conditions. The comparative study of the ABS mode and manual mode against wheel speed and vehicle speed is predicted in different time intervals. The smart hybrid ABS control provides better response in comparison to conventional braking. It is experimentally proved that the acclaimed antilock braking system reduces the stopping distance in comparison to the manual braking unit.

Problems and Perspectives of Implementation of Metalmatrix Composition Materials in Automotive Industry

In this paper we studied possible problems and perspectives of deployment of aluminum-based composite alloys in automotive industry.Aluminum-based composite alloys thanks to their high elastic strength combined with a relatively low mass density, good casting and tribological properties with respect to conventional alloys were implemented in automotive industry over 20 years ago already.These alloys successfully substitute steel, cast iron and titanium alloys in engine, suspension, braking units. However high final cost of auto-components made of strengthened aluminum alloys limits its applications in the industry.In this work we presented the examples of aluminum-based composite alloy technology that reduces the production costs of final product.

Problems and Perspectives of Implementation of Metalmatrix Composition Materials in Automotive Industry

In this paper we studied possible problems and perspectives of deployment of aluminum-based composite alloys in automotive industry.Aluminum-based composite alloys thanks to their high elastic strength combined with a relatively low mass density, good casting and tribological properties with respect to conventional alloys were implemented in automotive industry over 20 years ago already.These alloys successfully substitute steel, cast iron and titanium alloys in engine, suspension, braking units. However high final cost of auto-components made of strengthened aluminum alloys limits its applications in the industry.In this work we presented the examples of aluminum-based composite alloy technology that reduces the production costs of final product.

Vehicular Speed Regulation through Autonomous Braking System Embedded with Smart Insurance Facility using Iot

The recent developments in the field of automotive engineering and the ease of automobile production has resulted in a drastic increase in the number of vehicles and subsequently heavy traffic congestion. This has naturally resulted in doubling of accidents due to negligence. The process of claiming insurances for the damages incurred is till date a very tedious and time-consuming process. Persons claiming pay-back from insurance policies even go up to the extent of faking documents or produce forged evidences to get monetarily benefitted. Till date there is no secure automotive system that provides safe driving through intelligent braking, combined with an IoT based insurance calculation smart device. The proposed idea provides a safety system to the driver through speed regulation that is primarily governed through an automatic braking unit. The system is centered with a microcontroller unit, which along with sensors interfaced, reads the vehicles around it and optimizes the speed of the vehicle. The autonomous braking system intervenes only when there is an emergency control of the vehicle required. An added feature to this autonomous unit is the smart insurance facility that ensures that insurances are claimed genuinely. The vehicle On-Board Diagnostics (OBD) is connected to cloud via IoT, which performs vehicle tracking continuously.. It collects data about the state of various parts, detection of any failure in the engine, signs like speed warnings and proximity levels and transmits the data automatically, which can be accessed using Android or iOS or a web browser. The data received, is then shared with the insurance providers and the clients, after which insurance procedures follow. Thus, the above hybrid system, ensures passenger safety and also aids in faster insurance claims for genuine cases of accidents, which can be done precariously based upon the magnitude of the accident.

Mathematical modeling trajectory of a ship as a control object in global planning

In today’s world of wars and pandemics, devices are needed that can control a ship without a human, solve complex navigational tasks, and carry cargo/people to/from the affected area. If it is a warship – to perform a combat mission without loss of personnel. Such devices require conditional classification of scenarios and the formation of global planning tasks in real time. A mathematical model of the global planning task has been elaborated. Changing the trajectory in real time is a change in the route matrix in global planning, which allows to rebuild the matrix of local planning. Each scenario is a coincidence of certain circumstances and conditions; circumstances and conditions are written in the form of programming code. It is proposed to use track matrices for global planning of the ship’s trajectory. The binary path matrix (incidence matrix) can vary depending on the operational scenario. There are 4 possible scenarios and a scenario matrix that shows the correlation between the scenario and the waypoints. The proposed elaboration does not contain a conflict of priorities. All global planning scenarios run on time. A sudden scenario is not included in the scenario matrix, but it stops the global planning task. The three-column filter moves the braking unit diagonally in the path matrix depending on the number of missed points and allows the vessel to stop in front of the correct vertex by moving the braking unit diagonally across the path matrix. The control device modifies the trajectory in accordance with the execution of a scenario. The vessel is considered to be a control object which, in accordance with the decision of the control device, changes trajectory and/or stops by active or passive braking. Relevant graphic simulations are presented in the article. Economic efficiency is calculated on the basis of open data on the salaries of the ship’s crew.

A small spacecraft motion control method employing inflatable braking units for deceleration while orbital flight prior to the atmospheric entry

A small spacecraft motion control method employing inflatable braking units for deceleration while orbital flight prior to the atmospheric entry